data not transferring when using cudamemcpy


I am performing a normal cudamemcpy function in my kernel, but the values inside my structure do not seem to be transferring onto the GPU correctly.

Here is the line of code:

cudaMemcpy(envreal_d,&envreal_,sizeof(struct envreal),cudaMemcpyHostToDevice);

envreal_ is the struct with all the data in it, and I have already allocated memory for envreal_d on the device. I just get zero values for everything. Could it be a memory problem?

thank you,

What is in the structure?

some arrays and an int:

extern struct fishinteger{

    int xstarty[100], xstartz[100];

    int numeggs;

} fishinteger_;